Airplane landing guide



April 23, 1935. F. J. ANDRE ET AL AIRPLANE LANDING GUIDE Filed Jan. l0, 1935 2. Sheets-Sheet l nventors,

l 4 a Cfttorneg w w W April 23, 1935. F. .1. ANDR ET Al.

AIRPLANE LANDING GUIDE Filed Jan. l0, 1933 2 Sheets-Sheet 2 wm mk Snventors,

(lttornegs PatentedApr. 23,` 1935 i i i UNITED STATES Pa'iEN'rv oFEicE y 1.99am f Frank J. andr, cniiegn Park. Gn., and imma c. stark, rnngiikpnie, N. Y.

Application January io, 1933, sensi-Naucalpan A' iciainn. (erin-352i v The object of this invention is to provide' a is a straight line of lights Gand Tprolonged' to simple but effective means whereby the pilot of a point adjacent to the sending station 3,. 'I'he an aircraft, approaching the general locus of a line of lights 6 and 1 is arranged at a normal landing field, in a fog, or under like unfavorable'- gliding angle, asFig. lindicates. Itis Suggested conditions as to visibility, and guided by such an that the lights `6 be-white electric lamps, winch 5 instrumentality as the presentlyexisting Demay be spaced one hundred feet'. apart. As'to the' partment of Commerce radio beam, may, as he lights .'l these may begreen electric lamps forv arrives near the sending station from which the 'about one hundred'feet from the lights 5, to indibeam proceeds, be guided by a novel combination cate that it is time to level off for a landing.

of objects bearing relation to visibility, to tne Then come 'red electric lamps for the next hun- 10 runway of the landing eld, information Jbeing dred feet, followed by one green-.light to indicate imparted as tov azimuth, altitude, time for checkthat therunway of the field l is near. Thence ing speed and trimming ship for landing, field the red lights are continuedvtdthe sending staboundaries, and' the various other factors that tion 3.; Somewhere along the first lineof lights G make for an accurate, safe and expeditious landand 1, one of them is rendered individually charl5 ing, acteristic, to. serve asa special marker, indicating It is within the province of the disclosure to to the. pilot that it is-time to throttle down, set improve generally and to enhance the utility of the stabilizer back and', ingeneral, trim the ship devices of that type to which the invention apfor landing. I

pertains. Beyond thesending station 3 there is 'a second 20 With the above and other objects in view, lline of lights, alined witlitheflrst, and extended which will appear as the description proceeds, between the beams `l 'and 4. The second line the invention resides in the combination and arvembodies lights 8, 9 and ID, The lamps 8 and g' rangement of parts and in the details of con- I0 may be spaced at intervals ofone hundred f struction hereinafter described and claimed, it feet. Thelights 8 maybe white electric lamps,'25 being understood that'changes in the precise emthe lights I0 may be white electric lamps, having bodiment of the invention herein disclosed, may a defined directional characteristic, and the be made within the scope of what is claimed, lamps 9 might'be red electric lamps. Alloi' these without departing from the spirit of the invenlamps are carried by towers or poles, or anything tion. i else that will raise them above obstacles inthe line 30 In the drawings: of iglmk Y Fig. 1 shows inelevation, one form of airplane The system shown in Fig. 1 presupposes a very landing guide Constructed ln aCCGldlm With' unfavorable chain of circumstances.v For iiithe invention; stance, the sending station 3 is notffar enough Fig. 2 iS a t0n plan; from the field l so that there is suiiicient time 35 Figs. 3, 4 and 5 are t0n PlanS illustrating modito trim for a landing, and therefore the line of atlOnS. lights 8, 9 and I0,'extending beyond the sending In Figs' i 91nd 2 aiiaiidiiig iieifi is shown at i station 3 is provided. Again, the ship might be and the sending station from which the beams 2 off the beams 2 and 4, but in the sector between 40 and 4 proceed is marked by the numeral 3 Aii them. Under such circumstances, the pilot has the boundary of the field I is located a line of the advantage of the second line of lights 8, 9 and lights 5' which may be eieeiiie iamps the iei'm lo. A11 of the lights, in either line, color the fog.

eieeiiie iamps" iiieiiiiiiie een tubes ei anything The lights lo being of n directional nature indiclse that will answer the purpose. This line may cate both the line of flight and the general location be dispensed with,1n,some instances. The lights 'of the Ship so Soon as they are picked up' and 4 5 ma be green neon lamps, elevated three feet or soi,I to clear snow that may be lying on tne from the lights iii' the remaining iights guide ground- The lights 5 may extend along the the pilot to the runway of the landing f ield. boundary of the field i as far as desired. In Fig. 3, Darts herelnbefore described have In most instances, or except where conditions been designated by numerals P1`V1011S1- Used. 50 require another arrangement, the entire system With the SllfllX a Here, th? Sending StatIOn 3G of lights is in the form of a T, the head whereof iS fal enugh from the landlng eld |a. S0 that is the lights 5. Extending from the intermediate the line of lights to the right 0f the Sending Staportion of the line of lights 5,-at right angles tion 3 in Fig. 1 may be dispensed with, for the thereto in the showing selected as an illustration, most part. The lights Illa, and the interposed 55 lights 9a are retained, and are extended backwardly from the station, along the beam 4a.

In Fig. 4, parts hereinbefore described have been designatedby numerals previously used, with the sumx b. In this form. the sending station 3b is far enough from the eld Ib, so that the line of lights to the right of the station 3 in Fig. 1 may be,.0mitted, but at the outer end of the line in Eig? 4,-the'lights Ib and the interposed liglits'bare employed, the line of lights lying exclusively between the field Ib and the sending station 3b.

Figure 5 presents an ideal condition, in that the beam 4c, and its reverse beam. lead directly to the field lc and its most available runway. Here the lights 6c and 1c are continued past the station 3c, along the beam laas are the lights 9c and Inc. In Fig. 5, parts hereinbefore described are designated by the numerals previously used, with the suill:i:,c.

In putting the invention into practice, the.

pilot, of course, will exercise the skill of his calling, regarding losing altitude, placing his ship' on the beam, and other matters relating to sound .and approved pilotage, rather than to the specic operation and function of the various mechanisms shown and described. f

Acknowledgment is made respecting the wellknown Department of Commerce plan of aiding blind landing, described in Research Paper No. 238 of October 1930, and nowa matter of common knowledge among experienced yers. According to the system referred to, 'a radio landing beam leads from the silent cone of the main long range radio beacon to the .landing field. The

-landing operation, under such a system, is effected by the observing of instruments. The observing of instruments, however, is not a natural way of acquiring knowledge. Skill of an unusual kind is required in making the observations, and

after the observations are made, further skill, and

skill-of a different sort, is required in interpreting the observations made.

The lag of instruments, however well constructed, and their liability to error, is something that has to be taken into consideration. Where the question of pilotage is concerned, no experienced pilot will place implicit conildence on the mechanical perfection of his instruments. As a simple example from an analogous calling, a shipmaster may have the deviation of his compass reduced to a minimum, by a skilled compassadjuster, yet he will miss no opportunity to try his compass on ranges, the bearing of which is known, nor will he fail to check his compass, by amplitude observations, or some other method, whenever possible. The practice of relying upon something other than the perfection of instruments is so well-known that the foregoing discussion of the matter perhaps has been unduly extended.

Reverting to the specific problem under consideration, a pilot coming in on the main radio beam may miss the silent cone, and be unable to pick up the radio landing beam, in the absence of a skill which is rare, and to be found only with experts, and not, by any means, with all experts.

In the device forming the subject matter of this application, the guiding of a plane from the silent cone of the main radio beams to the runway of the eld, does not call for experience in the observation of instruments, or in the interpretation of data derived from instruments. Rather, it depends upon ocular observation of simple conditions external to the ship, and independent of instruments. Stated in plain language, pilots are accustomed to land, governed by what they see about them, external to the ship. This is, and probably long will be, the basis of training for all landings, blind or otherwise. It has a rational foundation, independently of the flying art, and that basis is the natural tendency to draw conclusions from the simplest sorty of observed phenomena. Forinstance, any one can tell by inspection that a surface is curved, unless the curvature is very slight. It requires an entirely different degree of skill, and a different and much more extensivetraining, to determine by a spherometer that the surface is curved. The advantages in favor of the system shown in this application are no less marked.

According'to the training of present day pilots, and in view of the training'that pilots will continue to receive, until the flying art is much more perfectly developed than it is at present, pilots look out of the machine, to see what is about them, when a difilcult landing is to be made. The time consumed while the eye is shifting from the instrument to objects external to the plane, and back again to the instrument, together with the change of focus in the eye, and the adapting of the eye to light conditions which are different within and without the plane, produce a lost timeperiod which is of importance. considering the high speed at which the plane is moving. There is, therefore, an obvious advantage in providing a means whereby the pilot, having arrived at the silent cone, may be guided to the margin of the field by a line of lights, which is something that calls neither for instrumental observation nor the Vinterpretation of instrumental readings.

Under present methods, it is necessary for the pilot, upon reaching the silent cone of the directional radio range beam, to retune his receiver to the dierent wave length of the landing beam,

' and then to circle while flying (blind) by instruments, in order to pick up this beam and to follow it down to a landing. 'I'his circling, when carried out near busy airports located in proximity to factory chimneys, radio towers. etc. aiways involves a risk of collision with other airplanes. or objects on the ground.

With a lineof fog-penetrating lights located along the ground, coincident with the vertical projection of the directional radio range beam and extending from a point along the course to the silent cone and thence to the landing field, there is produced an actual overlap of the radio and visible light systems which would enable the pilot, on approaching the silent cone and when still on a straight course, to change from the instruments in his cockpit over to his natural method of orlentation by outside visual reference points. I'he pilot would then, by outside. reference, be enabled to proceed directly along these lights into his actual landing with greater ease, lsafety and dispatch.

Having thus described the invention. what is claimed is:

1. Means for facilitating the blind landing of aircraft, comprising a landing field, al source of radio beams external to the field but located suftlciently close to the neld to be directionally characteristic of the field, and a guiding link between said source and the field and visible to an operator within a plane, said link comprising a line of lights external to the held and leading from said source to the margin of the field.

2. Means for facilitating the blind landing of 7 aircraft, constructed as set forth in claim 1, and

wherein a portion of the line of lights serves as a guide for a landing airplane and extends along said one of the radio beams from said source to the margin of the field.

3. Means for facilitating the blind landing of aircraft, constructed as set forth in claim 1, and wherein a portion of the line of lights extends along said one of the radio beams and `serves as a course guide for a landing airplane, said line also extending beyond said source,l and in a direction away from the eld. 

